Log scrubbing machine



Emu. 3, 1935. c. H. BURR LOG SCRUBBING MACHINE Filed June 3, 1933 2 Sheets-Sheet l Jnvere 202".

C. H. BURR LOG SCRUBBING MACHINE Filed June 5, 1955 M 2 4 5 0a ||r- 4 2 r 7 n0 [PH 2 a z 7. 0 0 m n W w H 4 8 e I m W a 4 v H q m LLllllhtQ. l l II I h I e o NH MW H 71 4 AV J M n w 4 4 0 4 4 Mm 5 1 5 +lLn mm mm w Dec, 3, 1935.

Patented Dec. 3, 1935 0 UNITED STATES PATENT OFFICE LOG SCRUBBING MACHINE Application June 3, 1933, Serial No. 674,202

2 Claims.

This invention relates to a system for grinding wood for paper pulp and for cleaning the pulp logs in their passage to the grinders.

The present invention is an improvement on the wood grinding system of my copending application Serial No. 572,000, filed October 30, 1931. In the wood grinding system of the said application a series of single-charge magazine grinders of the type shown in the Whitcomb patent issued May 6, 1930, No. 1,570,013, are arranged in spaced parallel rows on opposite sides of a trough that is somewhat wider than the length of the pulp log and along which a current of water flows from a storage pond and conveys the logs along the trough and automatically positions them for insertion in the magazines of the grinders with minimum labor. The present invention is associated with and is especially adapted for a wood grinding system of this type.

While the WOOd that is supplied to the grinders is debarked, the debarked logs may be stored in a pile for a considerable length of time prior to use and so are exposed to and can accumulate considerable dirt that is blown thereon by the winds or that falls thereon in the form of cinders from smoke stacks. The logs also can have a considerable amount of loose bark or slime collected thereon. If this dirt is ground into the pulp during the grinding of the logs it makes a dark spot in the sheet formed from the pulp and lowers the quality of the finished product and hence its presence on the log is undesirable.

It is an object of the present invention to subject the logs passing along the trough to the grinders, in the system of my prior application, to an automatic cleaning and scrubbing process to remove foreign matter that is adherent to the surface of the log before the log is loaded into any grinder.

A further object of the invention is the provision of rotating scrubbing brushes disposed close above or, preferably, dipping somewhat under the surface of the water in the trough along which the logs are floated and so arranged that each log is brought into contact with the rotating brushes, which brushes rotate upon and thereby scrub the surface of the log and detach or loosen any foreign matter thereon and at the same time rotate the log in the water so that the water washes off the detached or loosened foreign matter.

Another object of the invention is the provision of a rotating brush for scrubbing the logs as they are carried along in the trough, the brush being so arranged that it can rise and fall freely Fig. 2 is an enlarged sectional view taken along 10 line 22 of Fig. 1.

Fig. 3 is a plan view of the cleaning apparatus. Fig. 4 is a sectional elevation taken along line 4-4 of Fig. 3.

Fig. 5 is a sectional detail of one of the cleaning 15 brushes.

The wood grinding and cleaning system embodying the present invention includes a series of double grinders I0 arranged in opposed spaced relation in parallel rows. Each grinder is of the type disclosed in the above identified Whitcombpatent and includes grinding pockets located on opposite sides of the grindstone and provided with pistons operating in cylinders l6 for forcing the wood in the pockets against the rotating stone. Each wood pocket has an upstanding open top storage magazine or hopper l8 that is adapted to hold sumcient wood for one charge only of the associated grinding hopper. The hopper is somewhat longer than the length of the logs it receives. are provided automatically to admit the charge of wood in the hopper into the grinding pocket when the pocket becomes exhausted of wood. All of the grinders are associated with a trough 20 in which a supply of logs is constantly maintained and from which logs can be removed and disposed into the empty hoppers of the grinders. Said trough 20 is located between the two rowsof grinders and is comprised of a bottom wall 22, and upstanding side walls 24, the trough being freely open its full width at the top. The trough is disposed in elevated position between the grinders on a framework 26 in such position that the logs floating in the water in the trough Means not necessarily shown 30 are at a higher elevation than the open tops of 45 the hoppers of the grinders. Each grinder hopper is provided with a chute 28 which is inclined downwardly from adjacent the top of the trough to its hopper so that a log in thetrough confronting the hopper can be easily removed from the trough and deposited in and slid down the chute into the hopper, the long dimension of the hopper being at right angles to the length of the trough. The framework 26 carries sidewalks 30 on opposite sides of the trough and between the rows of grinders along which an attendant can pass and there are bridges, not shown, across the trough between the chutes of each pair of hoppers on which a workman can stand for transferring logs from the trough into the chutes of the grinders. The trough at its entrance end communicates with a large storage pond 34 out of which a current of water is constantly flowing into and along the trough. The water flows over a dam 36 at the other end of the trough and thence through a discharge pipe 38 to waste. The depth of the water in the trough is always such that there is a substantial clearance between the floating logs and the bottom of the trough. The storage pond 34 contains at one end either a pile of logs 40 sufficient, for instance, for a day's supply of wood for the grinders, or has a chute 42 which continually discharges logs into the pond from some other part of the plant. An attendant at the head end of the pond keeps logs from the pile 40, or from the chute 42, moving in the direction of the entrance of the trough. A second attendant at the trough entrance directs logs into the trough and arranges them so that they lie across the trough. Since the width of the trough is adapted to be not much greater than the length of the logs, the trough keeps the logs as thus arranged and the current of water advances them down the trough. The foremost log comes to rest against the dam 36 and the other logs are thus held stationary, one against the other, in the trough. When a log convenient to a chute 28 is removed from the trough the current of water automatically advances the logs to fill up the empty space and thus keeps a constant supply of logs in position to be deposited in the hoppers of the grinders. The system as thus described is essentially the wood grinding system of my aforesaid application.

In accordance with the present invention means are provided to scrub and clean the surfaces of the logs in the trough and prior to their becoming positioned in front of-the grinders. The cleaning apparatus preferably is so positioned between the pond 34 and the first pair of grinders that there is a substantial length of trough between the first pair of chutes 28 and the cleaning apparatus in which logs can float freely out of contact with each other. The cleaning and scrubbing apparatus, see especially Figs. 2, 3, and 4, includes a horizontally-disposed supporting frame which overlies the top of the trough and has spaced side members 44, front and rear end cross members 46 and 48, intermediate cross members 50 and a further cross member 52 which is pivoted in bearings 54 carried by and upstanding above the top of the side walls 24 of the trough, so that the frame can swing vertically about the horizontal axis of the cross member 52. Bearing blocks 56 are carried by the side members of theframe-at the rear end thereof and shafts 58 and 60 are journalled in said blocks and are extended transversely of the frame. Each shaft supports a rotatable wire brush cylinder 62 composed of a plurality of wire brush discs 64, see Fig. 5, disposed on its supporting shaft between spacers 66 that are thin enough to permit the wires of the brushes to present a substantially continuous periphery in the cylinder, the wire brushes and spacers being clamped together between a collar 68 fixed to the shaft and a nut I screw threaded on the shaft. The shafts 58 and 60 extend different distances beyond the same side of the frame and are provided with pulleys 12 which are engaged by driving belts 14 that pass around a pulley 16 on the shaft of a driving electric motor 18. Said motor is supported on a suitable frame 80 on the side of the pivotal axis of the frame opposite the brushes so as to tend to counter-balance the overhung weight of the frame and brushes. The frame is further counter-balanced by a weight 62 carried on the free end of arm 84 that is passed over the end cross member 48 and under the cross member 52. The weight of the frame on the brush side of its axis is intended to over-balance the weight of the frame on the other side of its axis so that the frame normally rests upon the top of the upstanding walls 24 of the trough in which position the lower portions of the revolving brushes preferably dip somewhat below the level of the water current in the trough. The brushes are rotated in the same direction by the motor 18, as indicated by the arrows Fig. 4, which direction is such as to advance the logs along the trough. A cover plate 86 overlies the rolls to shield them from unintentional access and also to prevent them from throwing water out of the trough and a canvas or other flexible apron 88 is suspended from the cross member 46 at the rear of the brushes down about to the level of water in the trough also to prevent the throwing of water. A guard plate 90 is suspended on a pivotally supported shaft 92 across the trough behind the apron to prevent expulsion of chips, bark and other parts of substantial mass from the trough by the brushes. As thus arranged a log that is carried down the trough by the water current therein comes in contact with the first rotating brush. The brush rotates in contact with the floating log and also rotates the log so that the brush scrubs the entire cylindrical surface of the log and detaches and loosens any dirt or foreign matter adherent thereto. The log rotates in the water and the water washes off the loosened dirt. The log ultimately passes under the first brush to the second brush, or is positioned between and is engaged by both brushes, Where the action is repeated. The rotating log is finally thrown clear of the second brush and spins freely in the water by the impetus given it by the rotating brush and thus washes off the loosened dirt. The clean log then passes along the trough by the water current therein and comes to rest against the stationary row of cleaned logs in the trough and ultimately is taken into a hopper. The dirt that is removed from the log passes along with the water and is discharged at the end of the trough. The brushes revolve in contact with the water and so are selfcleaning. Ordinarily the brush-carrying frame rests upon the top walls of the trough during the scrubbing action of the brushes on the logs. When an extra large log passes into the engagement of the brushes, however, the brushes climb upon the log and the frame rises while maintaining the brushes in engagement with the log. When the log passes under and free of the brushes the frame falls into its normal low posi- 5 tion. Thus the device adapts itself to logs of all diameters.

I claim:

1. Pulp log cleaning apparatus comprising a trough having a current of water that floats the 7 logs crosswise down the trough, a rising and falling rotating brush disposed crosswise of the trough in position to ride upon and scrub the surfaces of and depress and rotate the advancing floating logs, and driving means for the brush. 7

2. Pulp cleaning apparatus comprising a trough adapted to contain a current of water in which logs are floated down the trough, a generally horizontal supporting frame disposed above the trough and having a horizontal pivotal support, a pair of rotatable brushes carried by said frame on one side of said pivotal support and extended transversely of said trough in position to be engaged by the advancing logs, and means including a brush driving motor carried by said frame on the other side of said pivotal support arranged to permit said frame to rise and fall in response to logs passing under said 5 brushes.

CHARLES H. BURR. 

